Paper-drying machine



B. D. CUPPAGE.

PAPER DRYING MACHINE.

APPLICATION FILED IuLY 27.1917.

SEC 7/ B. D. COPPAGE.

P APER DHYING MACHINE.

APPLICATION FILED IuLY 21. I9II.

Patented Dec. 7, 1920.

3 SHEETS-SHEET 2.

B. D COP'PAGE.

PAPER DRYNG MACHINE.

APPLICATION FILED IuLY 27. |917.

Patented Dec. 7, 1920.

3 SHEETSSHEET 3.

www. D m

54m/Daum BENJAMIN DENVER COPPAGE OF WILMINGTON, DELAWARE.,

PAE'ER-DRYING MACHXNE.

Specification of Letters Patent.

Patented Dee.. 7, 192@ Application eiea'nuy er, 1917. serial no. ieaiia To aZZ 'whom t may concern Be it lrnown that l, BnNJAMiN DaNi/nn Corman, a citizen oli' the United States et America, and a resident ot Wilmington, Delaware, have invented a new and useful improvement in Paper-Drying Machines, which invention is fully set forth in the 'tollowing specilication.

The present invention relates to improvements in paper-drying machines, and more particularly to means :tor distributing heat to the paper-drying cylinders whereby tl e cylinders may receive heat in proportion to their demands, thereby increasing the eiliciency of: the dryer without detracting from the quality of the paper and for removing water ol condensation from the system in a more effective manner.

t is customary in paper making to pass the web of paper containing about 67% of water, after leaving the press-rolls of the paper-making machine, to steam heated cylinders arranged in staggered relation in two or more rows. The heated surfaces oi' the cylinders convert the water in the web into vapor the removal of which is facilitated by exposing opposite surfaces ot the web to the atmosphere while advancing to the calender end of the series.

Heretofore it has been the practice to heat the cylinders by delivering steam :from a manifold to the several drying cylinders and to remove the water of condensation formed in each cylinder through a common discharge main. @wing to the greater heatabsorbing capacity of the wet end ot the web as compared 'with the dry end, the demand on the steam supply main is greatest in those cylinders in contact with the wet web and least in those cylinders in contact with the dry web. 'llo meet this demand, the steam supply sometimes becomes excessive due to lack of care or attention ot the operator, or to other cause. Steam pressure therefore rises in all the cylinders. The pressure and temperature in the cylinders at the calendering end ot the series rises abnormally high since they utilize little of the latent heat of the steam in evaporatingwater in the web. This rise ot teinperature often injures the quality of the dry paper, while the increased pressure causes a rise of pressure in the water discharge line connected to the cylinders, soon becoming greater than the pressure in those drying cylinders in which the latent heat of the rsteam is used tor drying the wet paper web. lhis back pressure causes water and air to be trapped in these cylinders, thereby cutting off their supply of steam and causing a drop in temperature sutlicient to render them temporarily useless.

As the result of my investigations, l have discovered that the temperature ot the drying cylinders in contact with the wet web may be materially increased without injury to the liber of the paper, provided the temperature in the cylinders near the calendering end is maintained at a temperature below that injurious to dry ber, and that, by a proper distribution of the heating inedium to the cylinders, lf am enabled to avoid trapping of water and air in the cylinders and can produce paper of a given quality while increasing the capacity of the drving cylinders. .lln a drier having thirty j two drying` cylinders receiving the web at 400 F. and delivering it at 1300 F. under normal conditions ot ventilation and tension of felt, 66% of the total steam used is condensed by the time the paper reaches the fourteenth cylinder.

My invention overcomes the objections noted above and secures the above objects by providing` a drying system in which the drying cylinders are divided into two or more groups, the cylinders in a group being supplied by a heating medium such as steam from a head common to the cylinders oic a group and providing a distributing valve, preferably ot my improved construction as herein described, connected to a source of heat and in multiple to other distributing valves which control the supply ot steam to the separate headers connected to cylinders in the several groups. The cylinders of each group preferably deliver water of condensation into collecting pipes individual to the groups from which the water passes to a well through a single trap as shown in Fig. 3 or through a plurality ot traps, as shown in lligs. 1, la.

The distributing valves are designed to sub-divide the original current -of steam into streams di'li'ering in current amount, depending on the needs ot the several groups of cylinders.

l have described my invention in connection with a paper-drying machine, but it is to be understood that it may be used in drying other materials such as cloth and other fabrics, and, while l have herein deasY scribed my particular form of valve and prefer to use the same in my system, it is to be understood that other forms ot valve capable of sub-dividing a fluid stream may be used Without departing from the spirit of my invention.

In -order that the invention may be more readily understood, reference is had to the accompanying drawings showing, by way of example, mechanical embodiments thereof', `but such drawings are intended to assist the description and not to define the limits of .the invention.

ln said drawings Figures 1 and 1a together show, partly in elevation and partly in diagram, a view ot a drier for a paper machine embodying my improvement Fig. 2 is a longitudinal sectional vievs7 showing the interior ot my improved distributing valve; and

Fig. .3 is a view similar to Figs. l and 1L showing a slightly different embodiment of my invention.

Figs. 1, 1a show a series of revolving drying cylinders designated 1 to 8 in recurring groups. The cylinders at the left of Fig. 1 receive the wet web of paper as it comes from the presser cylinders (not shown), while the web leaves the cylinders at the right of Fig. la in a dry condition suitable to go :to ithe calender rolls. Heating fluid such as steam is distributed to the cylinders through a system of valve-controlled pipes arranged in the following manner. Each cylinder of .the first two sections 1, 2 is connected through pipes 9 with a header 10. The .cylinders of the remaining groups are connected to header 11. Each header 10, 11 is provided with a T-distributing valve 12, 13, the interior construction of which.. is shown in Fig. 2. Steam is supplied to these valves through a primary header 14 also provided with a T-distributing valve 15 preferably receiving exhaust steam from an engine. .116 and 17 are .pneumatic diaphragm valves operated by la source oi' fluid pressure controlled by va `device 18 affected by the temperature of the drier or driers to which it is attached. Valve 16 controls the exhaust to the atmosphere and valve 17 controls the supply to the T-distributing valve 15. As these valves and their controlling means fo-rm no part ofthe present invention, detailed description is deemed unnecessary.

19 is a live steam supply pipe for use in supplementing the exhaust steam supply `and for y'furnishing live steam to the felt driers, one of which is diagrammatically indicated above cylinder 7 of the :first group ot' cylinders. Valves '2l are .provided in the live steam -pipe 19 and are of the same type Yas shown for 4controlling the exhaust steam supply and, as they are kof known construetion, detailed description is deemed unneces sary.

rl`he drying cylinders are provided with a vdrainage system for removing water oi' condensation, including a series of collecting headers 22 one for each section of cylinders, each header being connected to the cylinders by drainpipes .Pipes 24 take the drainage from the headers and deliver through suitable automatically controlled traps, diagrammatically indicated, to a hot well through a main 25. In order to permit the escape of air which accumulates in the collecting pipes, vents 22 are provided therein.

rlhe operation oi the system as thus far described is as follows Assuming that the drier is being used in connection with a paper-making machine having tour sections ot drying cylinders, the T-distributing valve 15 is set at such position that about two-thirds of the exhaust steam coming from the engine is directed into the lett-hand section of header 1.4, the remaining portion being directed to the right-hand section ot the header let. At the same time T-distributing valve l2 is set to further distribute the left-hand stream ot steam coming from valve 15 into two unequal portions, the ylarger portion going to supply the cylinders constituting section l, while the smaller subdivision goes into the right-hand section of header 10. It will thus be seen that sections 1 and 2 of the drying` cylinders are supplied with steam distributed in accordance with their demands, the first group of cylinders receiving a larger quantity than the second group. The third group of cylinders are connected with the lett-hand section of header 11 which receives a divided portion of the steam I )assing to the right of T-distribnting valve 15. This is accomplished by setting T-distributing valve 13 to deiieet one portion of the supply to the left of valve 12:3 and the other portion to the right. The larger portion, for reasons explained above, passes to the lett where the demand 'for heating is greater than at the end cylinders constituting group el, but is less than that supplied to the cylinders of the second section. The last seetion of cylinders is supplied with the least amount of steam suficient to complete the drying operation.

y means of this system of heat distrihu tion, the wet end oi the paper web suhjected to rapid evaporation at a regulated temperature and, as it progresses through the drier, it progressively parts with moisture, the supply of heat being progressively decreased as the demand for heating diminishes. Distribution of the steam supply can thus be so regulated and maintained that the pressure in the water line will be constant. if it is a common water line, or can be varied if the water line is subdivided, in which ease it is possible to carry different pressures and different temperatures in each section of the dry part. Should the supply of exhaust steam not be sufficient to supply the cylinders with heat, live steam may be introduced into the system through pipe 19. This supply is shown as being automatically controlled by a thermostat 18 located in the drying room, but it may be hand-controlled if desired.

The water of condensation which would otherwise accumulate in the system is taken off from the cylinders of each section through headers 22 individual to each section and delivered through trap devices 25 to the main 25, from which it escapes to a hot well.

The T-distributing valve shown in Fig. 2 comprises a conduit 26 having a side connection 27, opposite the opening of which is a valve member 28 fast to a shaft 29 having bearings in the walls of the conduit and provided with projections 30, 3l exterior to the ,conduit 26 and housed in a-casing 32. This casing is provided with a closure 33 through which pass screws 34:, 35 designed to engage projections 30, 31 and regulate the movement of the valve member 28. Seats 36, 37 are provided in the conduit passage for receiving the valve member.

The construction shown in Fig. 3 is like that shown in Figs, 1 and la, except that thc valves controlling the steam supply are hand-operated and a single trap is shown for taking care of the water of condensation discharged from the main 25.

While the drawings show, by way of illustration, the use of four water-collecting headers in the above described system, it is to be understood that the invention is not intended to be limited to this particular num ber.

What is claimed is 1. In combination, a plurality of drying cylinders, a plurality of separate headers each individual to a plurality of cylinders and having pipe connections therewith, and a distributing valve having an inlet pipe connection designed to connect with a source of heated fluid and having outlet pipes connected in parallel with said headers.

2. In combination, a plurality of drying cylinders, each having a dischage pipe, a plurality of separate headers each individual to a plurality of cylinders and having pipe connections therewith, and a distributing valve having an outlet pipe connection designed to connect with a source of heated Huid and having outlet pipes connected in parallel with said headers.

3. In combination, a plurality of drying cylinders, a plurality ofseparate headers, distributing valves therefor, said headers being individual to a plurality of cylinders and having pipe connections therewith, and another distributing valve having an inlet pipe connection designed to connect with a source of heated fluid and having outlet pipes connected in parallel with said headers through said first-named valves.

4. In combination, a plurality of drying cylinders each having a discharge pipe, a plurality of separate headers, distributing valves therefor, said headers being individual to a plurality of cylinders and having pipe connections therewith, and another distributing valve having an inlet pipe connection designed to connect with a source of heated fluid and having outlet pipes connected in parallel with said headers through said first-named valves.

5. In combination, a plurality of drying cylinders, a plurality of headers each individual to and having pipe connections with a plurality of cylinders and having a distributing valve located intermediate the ends of the headers and another distributing valve having a pipe connection designed to connect with a source of heated fluid and provided with outlet pipes connected in par- 'allel to said headers through said first-named valves.

6. In combination, a plurality of drying cylinders each having a discharge pipe, a plurality of headers each individual to and having pipe connections with a plurality of cylinders, and having a distributing valve located intermediate the ends of the headers and another distributing valve having an outlet pipe connection designed to connect with a source of heated fluid and provided with outlet pipes connected in parallel to said headers through said first-named valves,

7. In combination, a plurality of drying cylinders, a valve casing having a pipe connection designed to be connected to a source of heated fluid, and other pipe connections designed to deliver fluid in parallel to said cylinders, and a valve member in the casing for controlling the quantity of heated fluid passing through said connections to groups of said cylinders.

8, In combination, a plurality of drying cylinders, a discharge main provided with a trap and having pipe connection with each cylinder, a valve easing having a pipe connection designed to be connected to a source of heated fluid, and other pipe connections designed to deliver fluid in parallel to said cylinders, and a valve member in the casing for controlling the quantity of heated fluid passing through said connections to groups of said cylinders.

In testimony whereof I have signed this specification.

BENJAMIN DENVER COIPAGEv 

